Emergency messages in watermarks

ABSTRACT

A device may be configured to signal information using watermarks. A device may be configured to determine a watermark message identifier. A device may be configured to receive a multimedia signal, parse a watermark message identifier, and receive fragment characteristic information in response to the value of the watermark identifier.

CROSS-REFERENCE TO RELATED APPLICATIONS Technical Field

The present invention relates generally to a system with audio-visual content watermarking.

Background Art

In many digital broadcasting systems, a broadcasting station transmits both streams of audio-visual (AV) content and one or more enhanced service data. The enhanced service data may be provided with the AV content to provide information and services or may be provided separately from the AV content to provide information and services.

In many broadcasting environments, the audio-visual content and the one or more enhanced service data is not received directly by an AV presentation device from the broadcasting station. Rather the AV presentation device, such as a television, is typically connected to a broadcast receiving device that receives the audio-visual content and the one or more enhanced service data in a compressed form and provides uncompressed audio-visual content to the AV presentation device.

In some broadcasting environments, the broadcast receiving device receives audio-visual content from a server (sometimes referred to as a Multichannel Video Programming Distributor (MVPD)). The MVPD receives an audio-visual broadcast signal from the broadcasting station, extracts content from the received audio-visual broadcast signal, converts the extracted content into audio-visual signals having a suitable format for transmission, and provides the converted audio-visual signals to the broadcast receiving device. During the conversion process, the MVPD often removes the enhanced service data provided from the broadcasting station or may incorporate a different enhanced service data that is provided to the broadcast receiving device. In this manner, the broadcasting station may provide the audio-visual content with enhanced service data, but the enhanced service data, if any, that is ultimately provided to the AV presentation device and/or the broadcast receiving device may not be the same as that provided by the broadcasting station.

Since the broadcast receiving device extracts audio-visual content from the signal received from the MVPD and provides only uncompressed audio-visual data to the AV presentation device, only enhanced service data provided to the broadcast receiving device is available. Furthermore, the same enhanced service data provided by the broadcasting station may not be provided to the broadcast receiving device and/or AV presentation device.

The foregoing and other objectives, features, and advantages of the invention will be more readily understood upon consideration of the following detailed description of the invention, taken in conjunction with the accompanying drawings.

SUMMARY OF INVENTION

One embodiment of the present invention discloses a method for receiving a watermark message, said watermark message containing at least one watermark message block, comprising the steps of: (a) receiving said at least one watermark message block; (b) determining a watermark message id from at least one of said at least one watermark message block; (c) determining a fragment characteristic information for each of said at least one watermark message block, wherein a length of said fragment characteristic information is based upon on a value of said watermark message id; (d) recovering said watermark message from said at least one watermark message block based upon said fragment characteristic information.

Another embodiment of the present invention discloses a method for receiving a watermark message, said watermark message containing at least one watermark message block, comprising the steps of: (a) receiving said at least one watermark message block; (b) determining a watermark message id from at least one of said watermark message block; (c) determining if a fragment characteristic information is present for each of said at least one of said said watermark message block, wherein said determining if a fragment characteristic information is present depends on a value of said watermark message id; (d) recovering said watermark message from said at least one watermark message block based upon said fragment characteristic information.

Another embodiment of the present invention discloses a device that includes a processor configured to receive a watermark message, said watermark message containing at least one watermark message block, comprising: (a) said device receiving said at least one watermark message block; (b) said device determining a watermark message id from at least one of said at least one watermark message block; (c) said device determining a fragment characteristic information for each of said at least one watermark message block, wherein a length of said fragment characteristic information is based upon on a value of said watermark message id; (d) said device recovering said watermark message from said at least one watermark message block based upon said fragment characteristic information.

Another embodiment of the present invention discloses a device that includes a processor configured to receive a watermark message, said watermark message containing at least one watermark message block, comprising: (a) said device receiving said at least one watermark message block; (b) said device determining a watermark message id from at least one of said watermark message block; (c) said device determining if a fragment characteristic information is present for each of said at least one of said watermark message block, wherein said determining if a fragment characteristic information is present depends on a value of said watermark message id; (d) said device recovering said watermark message from said at least one watermark message block based upon said fragment characteristic information.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 illustrates a system with enhanced service information.

FIG. 2 illustrates another system with enhanced information.

FIG. 3 illustrates a data flow for a system with enhanced information.

FIG. 4 illustrates another system with enhanced information.

FIG. 5 illustrates a watermark payload.

FIG. 6 illustrates another watermark payload.

FIG. 7 illustrates relationships between watermark payloads.

FIG. 8 illustrates relationships between watermark payloads.

FIG. 9 illustrates relationships between watermark payloads.

FIG. 10 illustrates another system with enhanced information.

FIG. 11 illustrates obtaining synchronization and maintaining synchronization.

FIG. 12 illustrates another watermark payload.

FIG. 13 illustrates SDO Private Data.

FIG. 14 illustrates metadata encapsulated within SDO Private data as SDO Payload using cmdID's.

FIG. 15 illustrates a watermark embedding system.

FIG. 16 illustrates a watermark extracting system.

FIG. 17 illustrates an expiry time value, an urgency flag, a severity indicator, and a certainty indicator of an emergency message.

FIG. 18 illustrates an exemplary emergency alert message.

FIG. 19 illustrates another exemplary emergency alert message.

FIG. 20 illustrates an exemplary set of certainty and severity codes.

FIG. 21 illustrates another exemplary emergency alert message.

FIG. 22 illustrates another exemplary emergency alert message.

FIG. 23 illustrates another exemplary emergency alert message.

FIG. 24A illustrates an exemplary bitstream syntax of the watermark message block.

FIG. 24B is an exemplary mapping of the field wm_message_id to watermark message wm_message( ).

FIG. 24C illustrates an exemplary syntax of wm_message( ).

FIG. 24D illustrates an exemplary syntax of the URI message.

FIG. 24E illustrates an exemplary mapping from value of uri_type field to types of URI.

FIG. 25A illustrates a flowchart of exemplary transmission of a field based on a transmitted key field value.

FIG. 25B illustrates a flowchart of exemplary reception of a field based on a received key field value.

FIG. 26A illustrates another exemplary bitstream syntax of the watermark message block.

FIG. 26B is an exemplary mapping of the field wm_message_id to watermark message wm_message( ).

FIG. 26C illustrates an exemplary syntax of wm_message( ).

DESCRIPTION OF EMBODIMENTS

(Definitions)

A uimsbf may represent an unsigned integer most significant bit first format.

When the value in Number of bits column equals to var it represents a variable length field.

A reserved field may indicate bits corresponding to the field are reserved for future use.

hexadecimal (also base 16, or hex) refers to a positional numeral system with a radix, or base, of 16 that uses sixteen distinct symbols, most often the symbols 0-9 to represent values zero to nine, and A, B, C, D, E, F (or alternatively a, b, c, d, e, f) to represent values ten to fifteen. Hexadecimal numbers often use the prefix “0x”.

x^(y) may be used to denote an arithmetic operation corresponds to an exponentiation operation i.e. x to the power of y. In other contexts, such notation may be used for superscripting not intended for interpretation as exponentiation.

Referring to FIG. 1, the system may include a content source 100, a content recognizing service providing server 120, a multi-channel video program distributor 130, an enhanced service information providing server 140, a broadcast receiving device 160, a network 170, and an AV presentation device 180.

The content source 100 may correspond to a broadcasting station that broadcasts a broadcast signal including one or more streams of audio-visual content (e.g., audio and/or video). The broadcast signal may further include enhanced services data and/or signaling information. The enhanced services data preferably relates to one or more of the audio-visual broadcast streams. The enhanced data services may have any suitable format, such as for example, service information, metadata, additional data, compiled execution files, web applications, Hypertext Markup Language (HTML) documents, Extensible Markup Language (XML) documents, Cascading Style Sheet (CSS) documents, audio files, video files, Advanced Television Systems Committee (ATSC) 2.0 or future versions contents, and addresses such as Uniform Resource Locator (URL).

The content recognizing service providing server 120 provides a content recognizing service that allows the AV presentation device 180 to recognize content on the basis of audio-visual content from the content source 100. The content recognizing service providing server 120 may optionally modify the audio-visual broadcast content, such as by including a watermark. In some cases, the AV presentation device 180 is a digital video recording device.

The content recognizing service providing server 120 may include a watermark inserter. The watermark inserter may insert watermarks which are designed to carry enhanced services data and/or signaling information, while being imperceptible or at least minimally intrusive to viewers. In other cases a readily observable watermark may be inserted (e.g., readily observable may be readily visible in the image and/or readily observable may be readily audible in the audio). For example, the readily observable watermark may be a logo, such as a logo of a content provider at the upper-left or upper-right of each frame.

The content recognizing service providing server 120 may include a watermark inserter that modifies the audio-visual content to include a non-readily observable watermark (e.g., non-readily observable may be non-readily visible in the image and/or non-readily observable may be non-readily audible in the audio). For example, the non-readily observable watermark may include security information, tracking information, data, or otherwise. Another example includes the channel, content, timing, triggers, and/or URL information.

The multi-channel video program distributor 130 receives broadcast signals from one or more broadcasting stations and typically provides multiplexed broadcast signals to the broadcast receiving device 160. The multi-channel video program distributor 130 may perform demodulation and channel decoding on the received broadcast signals to extract the audio-visual content and enhanced service data. The multi-channel video program distributor 130 may also perform channel encoding on the extracted audio-visual content and enhanced service data to generate a multiplexed signal for further distribution. The multi-channel video program distributor 130 may exclude the extracted enhanced service data and/or may include a different enhanced service data.

The broadcast receiving device 160 may tune to a channel selected by a user and receive an audio-visual signal of the tuned channel. The broadcast receiving device 160 typically performs demodulation and channel decoding on the received signal to extract desired audio-visual content. The broadcast receiving device 160 decodes the extracted audio-visual content using any suitable technique, such as for example, H.264/Moving Picture Experts Group-4 advanced video coding (MPEG-4 AVC), H.265/High efficiency video coding (HEVC), Dolby AC-3, and Moving Picture Experts Group-2 Advanced Audio Coding (MPEG-2 AAC). The broadcast receiving device 160 typically provides uncompressed audio-visual content to the AV presentation device 180.

The enhanced service information providing server 140 provides enhanced service information to audio-visual content in response to a request from the AV presentation device 180.

The AV presentation device 180 may include a display, such as for example, a television, a notebook computer, a digital video recorder, a mobile phone, and a smart phone. The AV presentation device 180 may receive uncompressed (or compressed) audio-visual or video or audio content from the broadcast receiving device 160, a broadcast signal including encoded audio-visual or video or audio content from the content source 100, and/or encoded or decoded audio-visual or video or audio content from the multi-channel video program distributor 130. In some cases the uncompressed video and audio, may be received via an HDMI cable. The AV presentation device 180 may receive from the content recognizing service providing server 120 through the network 170, an address of an enhanced service relating to the audio-visual content from the enhanced service information providing server 140.

It is to be understood that the content source 100, the content recognizing service providing server 120, the multi-channel video program distributor 130, and the enhanced service information providing server 140 may be combined, or omitted, as desired. It is to be understood that these are logical roles. In some case some of these entities may be separate physical devices. In other cases some of these logical entities may be embodied in same physical device. For example, the broadcast receiving device 160 and AV presentation device 180 may be combined, if desired.

Referring to FIG. 2, a modified system may include a watermark inserter 190. The watermark inserter 190 may modify the audio-visual (e.g., the audio and/or video) content to include additional information in the audio-visual content. The multi-channel video program distribution 130 may receive and distribute a broadcast signal including the modified audio-visual content with the watermark.

The watermark inserter 190 preferably modifies the signal in a manner that includes additional information which is non-readily observable (e.g., visually and/or audibly) in the form of digital information. In non-readily observable watermarking, the inserted information may be readily identifiable in the audio and/or video. In non-readily observable watermarking, although information is included in the audio-visual content (e.g., the audio and/or video), a user is not readily aware of the information.

One use for the watermarking is copyright protection for inhibiting illegal copying of digital media. Another use for the watermarking is source tracking of digital media. A further use for the watermarking is descriptive information for the digital media. Yet another use for the watermarking is providing location information for where additional content may be received associated with the digital media. Yet another use is to identify content and content source that is being viewed and the current time point in the content, and then allowing the device to access the desired additional functionality via an Internet connection. The watermark information is included within the audio-visual content itself, as distinguished from, meta-data that is delivered along with the audio-visual content. By way of example, the watermark information may be included by using a spread spectrum technique, a quantization technique, and/or an amplitude modulation technique.

Referring to FIG. 3, an exemplary data flow is illustrated. The content source 100 transmits a broadcast signal including at least one audio-visual content and an enhanced service data 201 to the watermark inserter 190.

The watermark inserter 190 receives the broadcast signal that the content source 100 provides and includes a readily observable and/or a non-readily observable watermark in the audio-visual content. The modified audio-visual content with the watermark is provided together with enhanced service data 203 to the MVPD 130.

The content information associated with the watermark may include, for example, identification information of a content provider that provides audio-visual content, audio-visual content identification information, time information of a content section used in content information acquisition, names of channels through which audio-visual content is broadcasted, logos of channels through which audio-visual content is broadcasted, descriptions of channels through which the audio-visual content is broadcasted, a usage information reporting period, the minimum usage time for usage information acquisition, statistics for sporting events, display of useful information, widgets, applications, executables, and/or available enhanced service information relating to audio-visual content.

The acquisition path of available enhanced service data may be represented in any manner, such an Internet Protocol (IP) based path or Advanced Television Systems Committee—Mobile/Handheld (ATSC M/H).

The MVPD 130 receives broadcast signals including watermarked audio-visual content and enhanced data service and may generate a multiplexed signal to provide it 205 to the broadcast receiving device 160. At this point, the multiplexed signal may exclude the received enhanced service data and/or may include a different enhanced service data.

The broadcast receiving device 160 may tune to a channel that a user selects and receives signals of the tuned channel, demodulates the received signals, performs channel decoding and audio-video decoding on the demodulated signals to generate an uncompressed audio-video content, and then, provide 206 the uncompressed audio-visual content to the AV presentation device 180. The content source 100 may also broadcast 207 the audio-visual content through a channel to the AV presentation device 180. The MVPD 130 may directly transmit 208 a broadcast signal including audio-visual content to the AV presentation device 180 without going through the broadcast receiving device 160. In yet another case some of the AV information may be sent to the AV presentation device 180 over a broadband connection. In some cases this may be a managed broadband connection. In another case it may be an unmanaged broadband connection.

The AV presentation device 180 may receive uncompressed (or compressed) audio-visual content from the broadcast receiving device 160. Additionally, the AV presentation device 180 may receive a broadcast signal through a channel from the content source 100, and then, may demodulate and decode the received broadcast signal to obtain audio-visual content. Additionally, the AV presentation device 180 may receive a broadcast signal from the MVPD 130, and then, may demodulate and decode the received broadcast signal to obtain audio-visual content. The AV presentation device 180 (or broadcast receiving device 160) extracts watermark information from one or more video frames or a selection of audio samples of the received audio-visual content. The AV presentation device 180 may use the information obtained from the watermark(s) to make a request 209 to the enhanced service information providing server 140 (or any other device) for additional information. The enhanced service information providing server 140 may provide, in response thereto a reply 211.

Referring to FIG. 4, a further example includes the content source 100 that provides audio-visual content together with enhanced service data (if desired) to the watermark inserter 190. In addition, the content source 100 may provide a code 300 to the watermark inserter 190 together with the audio-visual content. The code 300 may be any suitable code to identify which, among a plurality of audio-visual streams, should be modified with the watermark. For example code=1 may identify the first audio-visual stream, code=2 may identify the second audio-visual stream, code=3 may identify the fourth audio-visual stream from ABC, code=4 may identify the fourth audio-visual stream from NBC, etc. The code may include temporal location information within the audio-visual content. The code may include other metadata, if desired.

The watermarked audio-visual content and associated data, signaling is provided by the watermark inserter 190 to the MVPD, which in turn may provide the watermarked compressed audio-visual content to the broadcast receiving device 160 (e.g., a set top box). The broadcast receiving device 160 may provide watermarked audio-visual content (e.g., typically uncompressed) to the AV presentation device 180. The AV presentation device 180 may include a watermark capable receiver 310 together with a watermark client 320. The watermark capable receiver 310 is suitable to detect the existence of the watermark within the audio-visual content, and to extract the watermark data from within the audio-visual content. The watermark client 320 is suitable to use the data extracted from the watermark to request additional data based thereon, and subsequently use this additional data in a suitable manner.

The AV presentation device 180 may use the code 300 from the extracted watermark to make a request to a metadata server 350. A code database 370 receives the data from the content source 100 that includes the code 300 and associated metadata 360. The code 300 and associated metadata 360 is stored in the code database 370 for subsequent use. In this manner, the code 300 that is provided to the watermark inserter 190 which is encoded within the audio-visual content is also stored in the code database 370 together with its associated metadata 360. In the event that the MVPD 130, or otherwise, removes the associated metadata or otherwise changes the associated metadata, it is recoverable by the AV presentation device 180 from the metadata server 350 which uses the provided code 351 to query the code database 370 and provide an associated response with the metadata 353 to the AV presentation device 180. The reply metadata provided by the metadata server 350 is used by the AV presentation device 180 to form a request 355 that is provided to the content and signaling server 380. The content and signaling server 380, in response to the request, provides selected content and signaling 357 to the AV presentation device 180. In general, the content and signaling server 380 may be different from the metadata server 350.

However, making a first request to the metadata server to obtain a response to the code provided, then subsequently using the metadata to provide a request to the content and signaling server 380 is burdensome, and prone to failure, due to the two different servers and/or requests that are utilized. Additionally it may increase the latency.

By way of example, the metadata may consist of one or more of the following syntax elements:

-   (1) location of content and signaling server (e.g., where is the     server, such as its network address. Examples of network addresses     are domain names, IPv4 address etc.); -   (2) protocol to be used for communication with the content and     signaling server (e.g., Hypertext Transfer Protocol—http, Hypertext     Transfer Protocol Secure—https etc.); -   (3) time code identifying a temporal location in the audio-visual     content (e.g., where the metadata should be associated with in the     audio-visual content); -   (4) time sensitive event trigger (e.g., an advertisement or an event     for a particular location in the audio-visual content); -   (5) channel identification (e.g., channel specific information;     local channel content); -   (6) duration over which the content and signaling server requests     are randomly carried out by client (e.g., for load balancing). For     brevity, this syntax element may also be referred to as duration for     content server requests; -   (7) etc.

The watermark(s) embedded in the audio-video content typically have a capacity to carry only a few bits of payload information when the watermarked audio-video broadcast has non-readily observable information. For relatively small payload sizes, the time code (element 3 above) and/or the location of the content and signaling server (element 1 above) tends to take on a significant percentage of the available payload leaving limited additional payload for the remaining data, which tends to be problematic.

To include sufficient metadata within the watermark, so that both the time code and the location information may be provided together with additional information, it may be desirable to partition the metadata across multiple watermark payloads. Each of the watermark payloads is likewise preferably included within different portions of the audio-visual content. The data extracted from the multiple watermark payloads are combined together to form a set of desirable information to be used to make a request. In the description below the term payload may be used to indicate watermark payload. Each of the syntax elements may be included within a single payload, spanned across multiple payloads, and/or fragmented across multiple payloads. Each payload may be assigned a payload type for purposes of identification. Further, an association may be established between multiple payloads belonging to the same or approximately the same timeline location. Also, the association may be uni-directional or bi-directional, as desired.

The desired time code data may be obtained from payload(s) that span across several temporal locations of the audio-visual content. Therefore some systems may establish rules to associate the determined time code with a particular temporal location of the audio-visual content. In an example the chosen temporal location may correspond to the temporal location at the end of a pre-determined watermark payload.

For example, the payload size may be 50 bits while the desirable metadata may be 70 bits, thus exceeding the payload size of a single watermark. An example of the desirable metadata may be as follows:

Location of content and 32 bits (Internet Protocol “IP” server (I) address) Application layer protocol (A) 1 bit (http/https) Time code (T) 25 bits (for 1 year of uniqueness with a granularity of 1 second) Time sensitive trigger (D) 1 bit (A value of 1 indicates the AV presentation device should query for interactive content. A value of 0 indicates the AV presentation device should not query for interactive content (e.g. as in time base trigger)). Channel identification (L) 9 bits Duration for content server 2 bits requests (R)

Another example of the desirable metadata may be as follows:

Location of content and server (I) 32 bits (IP address) Application layer protocol (A) 2 bit (00 = http/01 = https, 10 = reserved, 11 = reserved) Time code (T) 25 bits (for 1 year of uniqueness with a granularity of 1 second) Time sensitive trigger (D) 1 bit Channel identification (L) 9 bits Duration for content server requests (R) 2 bits

One manner of partitioning the metadata is to include the content and signal server communication information (CSSCI) in one payload and timeline information in another payload. The CSSCI payload may include, for example, where information (e.g., location of content and signaling server), association information (e.g., an identifier to associate the CSSCI payload with one or more other payloads), and how information (e.g., application layer protocol, duration for content server requests). The timeline information may include, for example, association information (e.g., an identifier to associate the timeline with one or more other payloads), when information (e.g., time code information), and which information (e.g., channel identification).

Referring to FIG. 5, an exemplary CSSCI payload is illustrated.

Referring to FIG. 6, an exemplary time location payload is illustrated. The term time location may be alternatively used in place of the term temporal location.

The payload type may be identified by the first bit, “Y”. When Y is set to 0 the payload corresponds to CSSCI payload and the 14 bit payload identifier (P) is used to label the CSSCI. When Y is set to 1 the payload corresponds to the temporal location payload and the 14 bit payload identifier (P) signals the corresponding CSSCI. As a result, different payload types with same payload identifier (P) value are associated with each other. The identifier R indicates a time duration over which to spread the content and signaling server requests. In yet another example “Y” may correspond to a 2-bit field where the value 00 indicates a CSSCI payload, the value 01 indicates a temporal location payload and the values 10, 11 are reserved for future use.

Referring to FIG. 7, an exemplary time line is illustrated. A first CSSCI type payload (e.g., CSSCI-0) has a first set of association information P while a second CSSCI type payload (e.g., CSSCI-1) has a second different set of association information P. Having two different association information P for CSSCI-0 and CSSCI-1 distinguish between and identify the two CSSCI payloads. A first time location payload (e.g., Timeline-0) has the first set of association information P that matches the association information P for CSSCI-0, a second time location payload (e.g., Timeline-1) has the same first set of association information P that matches the association information P for CSSCI-0, a third time location payload (e.g., Timeline-2) has the same second set of association information P that matches the association information P for CSSCI-1. In this manner, CSSCI-0, Timeline-0; CSSCI-0, Timeline-1; and CSSCI-1, Timeline-2 are associated together as pairs having spanned watermarked information. This permits the same CSSCI type payload to be used for multiple different time location payloads.

As illustrated, each temporal location payload is associated with a previously received CSSCI type payload, and thus unidirectional in its association. In the event that a previous CSSCI type payload matching a temporal location payload is not available, then the system may be able to determine that a packet has been lost or otherwise the watermarking was not effective. The loss of watermarking data occurs with some frequency because the audio-video content tends to be modified by audio-video transcoding, such as to reduce the bitrate of the audio-video content.

Referring to FIG. 8, an exemplary time line is illustrated. A first CSSCI type payload (e.g., CSSCI-0) has a first set of association information P while a second CSSCI type payload (e.g., CSSCI-1) has a second different set of association information P. Having two different association information P for CSSCI-0 and CSSCI-1 distinguish between and identify the two CSSCI payloads. A first time location payload (e.g., Timeline-0) has the first set of association information P that matches the association information P for CSSCI-0, a second time location payload (e.g., Timeline-1) has the same first set of association information P that matches the association information P for CSSCI-0, a third time location payload (e.g., Timeline-2) has the same second set of association information P that matches the association information P for CSSCI-1. In this manner, CSSCI-0, Timeline-0; CSSCI-0, Timeline-1; and CSSCI-1, Timeline-2 are associated together as pairs having spanned watermarked information. This permits the same CSSCI type payload to be used for multiple different time location payloads. As illustrated, two of the temporal location payloads are associated with a previously received CSSCI type payload, and one of the CSSCI type payloads are associated with a subsequently received Temporal location payload, and thus bidirectional in its association. In the event that a corresponding CSSCI type payload matching a temporal location payload is not available, then the system may be able to determine that a packet has been lost or otherwise the watermarking was not effective. Similarly, in the event that a corresponding timeline type payload matching a CSSCI payload is not available, then the system may be able to determine that a packet has been lost or otherwise the watermarking was not effective. The loss of watermarking data occurs with some frequency because the audio-video content tends to be modified by audio-video transcoding, such as to reduce the bitrate of the audio-video content.

In an example, a CSSCI type payload (e.g. CSSCI-0) has two sets of association information P0 and P1. A time location payload, e.g. Timeline-0, has two sets of association information P0 and P1 that matches the association information P0 and P1 for CSSCI-0. In this example a bidirectional association exists for the pair CSSCI-0, Timeline-0 where P0 points to CSSCI-0 and P1 points to Timeline-0.

The number of bits assigned to the payload identifier (P) may be modified, as desired (e.g., for a desired robustness). Similarly, the number of bits assigned to I, A, T, D, L, and R may be modified, as desired.

In an example, the AV presentation device 180 may maintain a list denoted by a variable listC of “c” most recently received CSSCI payload(s). “c” may be provided in the watermark, if desired, or otherwise set by the system. In this manner, the AV presentation device 180 may only have to maintain a limited number of CSSCI payloads in memory. In the case that c=1, then once a CSSCI payload is received it remains in effect until another CSSCI payload is received, as illustrated in FIG. 9. A loss of a CSSCI payload may be detected using the payload identifier (P), for example, the temporal location payload contains a P that does not correspond to any of the CSSCI payloads in listC. In this manner, the same user experience may be achieved across different AV presentation devices 180.

In an example, the AV presentation device 180 may maintain more than one list of received CSSCI payload(s). Each list may differ in size and may be maintained (i.e. addition/removal of entries within the list) using a differing set of rules. It is to be understood, that this does not preclude the possibility that a subset of lists may have same size and/or same maintenance rules. As an example, there may be two lists maintained by 180 where one list contains “c1” most recently received CSSCI payload(s) where each payload is received at an interval of “0” CSSCI payload(s); while the other list contains “c2” most recently received CSSCI payload(s), where each payload is received at an interval of “d” CSSCI payload(s).

Referring to FIG. 10, a modified system may include the content source 100, the watermark inserter 190, the MVPD 130, the broadcast receiving device 160, and the AV presentation device 180 together with its watermark capable receiver 310 and watermark client 320. The content server 400 may be modified to include the code database 370, the metadata server 350, and the content and signaling server(s) 380. The code 300 and metadata 360 is provided to the content server 400 by the content source 100. The content and signaling data is provided to the content and signaling server(s) 380.

The AV presentation device 180 may provide a code in a request based upon the decoded one or more watermarks from the audio-video broadcast. The content server 400 receives the request with the code from the AV presentation device 180. The metadata server 350 then parses the received code request and based upon information from the code database 370, makes a request to the content and signaling server(s) 380 to determine the content and signaling information which is then provided to the AV presentation device 180. In this manner, the AV presentation device 180 only needs to make a single request to a single content server 400, which in turn provides the response to the AV presentation device 180. It is to be understood that the different functions of the content server 400 may be achieved by combining the existing functions together, separating the existing functions into more components, omitting components, and/or any other technique.

A http and/or https request URL (that will be sent to the content server 400) corresponding to payload(s) in FIG. 5 and FIG. 6, when time sensitive trigger D equals to 1, may be defined as:

If A is equal to 0 then the http request URL is:

http://IIIIIIII.IIIIIIII.IIIIIIII.IIIIIIII/LLLLLLLLL?time=TTTTTTTTTTTTTTTTTTTTTTTTT

Otherwise, the https request URL is:

https://IIIIIIII.IIIIIIII.IIIIIIII.IIIIIIII/LLLLLLLLL?time=TTTTTTTTTTTTTTTTTTTTTTTTT

where IIIIIIII.IIIIIIII.IIIIIIII.IIIIIIII above corresponds to the 32-bit IP address signaled in CSSCI payload.

In an example, the subset of URL that specifies information such as: the content server location, the communication protocol, communication port, the login information, the folder on the content server are carried in a designated payload type.

In some implementations a value of a syntax element may be derived using a decoding process which may access information spanning multiple payloads. For example, the time code may be fragmented into multiple watermark payloads and then reassembled to construct a complete time code. In an example, the time code may correspond to a temporal location within the audio-visual content. In an example, the time code may correspond to timeline data of the audio-visual content.

For example, the payload size may be 50 bits while the desirable metadata may be 66 bits, thus exceeding the payload size of a single watermark. An example of the desirable metadata may be as follows:

Location of content and server (I) 32 bits (IP address) Application layer protocol (A) 1 bit (http/https) Time code (T) 25 bits (for 1 year of uniqueness with a granularity of 1 second) Time sensitive trigger (D) 1 bit Channel identification (L) 5 bits Duration for content server requests (R) 2 bits

Another example of the desirable metadata may be as follows:

Location of content and server (I) 32 bits (IP address) Application layer protocol (A) 2 bit (00 = http/01 = https, 10 = reserved, 11 = reserved) Time code (T) 25 bits (for 1 year of uniqueness with a granularity of 1 second) Time sensitive trigger (D) 1 bit Channel identification (L) 5 bits Duration for content server requests (R) 2 bits

Referring to FIG. 11, a state transition diagram illustrates one technique to calculate the time code. To obtain a time code synchronization a number of consecutive payloads starting with a payload type “start sync”, is followed by payloads of type “not start sync”, with a total being equal to “r”. By using the total of “r” consecutive payloads, each having some time information contained therein, the time synchronization may be determined by calculating an anchor time. After calculating the anchor time code, the time code may be updated by receiving additional payloads that include partial time code information therein in such a manner that does not require receiving another total of “r” consecutive payloads to determine the next time code. One technique to achieve this time synchronization is to partition the time code in consecutive payloads and an incremental time code in each of the consecutive payloads. When the synchronization is lost, such as by changing the channel, the obtain synchronization process is performed. A video display device when first turned ON enters the initial “obtaining synchronization” state.

Referring to FIG. 12, an exemplary structure of a watermark payload is illustrated. Z indicates the payload type, where Z equal to 1 indicates the start of the time sync and Z equal to 0 indicates not start of time sync. S indicates the time sync payload bits used in determining absolute time code. M indicates the time sync payloads bits used in maintaining the time code.

By way of example, the AV presentation device 180 may receive n=7 consecutive watermark payloads where the first payload has Z=1 while the subsequent watermark payloads have Z=0. The bits corresponding to “SSSS” are extracted from (t−n+1)^(th) to t^(th) watermark payload and concatenated together to obtain a 28 bit representation of the time code “T_(t)” of a temporal location. The anchor time code “C_(t)” is also set to “T_(t)”. “T_(t)” may be represented as SSSS_(z=1,t-n+1) . . . SSSS_(z=0,t-1)SSSS_(z=0,t); “C_(t)”=“T_(t)”. In another example, constants may be added (to select a future time) and/or multiplied (to change the granularity) to the derived values. In yet another alternative example, the derived values are mapped to another value by use of a mapping function.

Once the initialization synchronization is obtained, the anchor time and payload time are updated using each payload. This may be performed, for example, as follows: T _(t) =f(C _(t-1) ,MMMM _(t)) C _(t) =g(T _(t))

Where, f represents a mapping function that takes as input 2 values and outputs 1 value; g represents a mapping function that takes as input 1 value and outputs 1 value; / represents integer division with truncation of the result toward zero, For example, 7/4 and −7/−4 are truncated to 1 and −7/4 and 7/−4 are truncated to −1. In an example: T _(t) =C _(t-1) +MMMM _(t) C _(t) =T _(t)

As described above, every “n” payloads the anchor time may also be determined using the bits corresponding to “SSSS”. The anchor time determined using “SSSS” must match the anchor time derivation above and can be used to verify the correctness of the maintained time code.

Since the watermark may span a non-zero time, the temporal location of the time code T_(t) may be determined by a set of rules, such as for example, T_(t) may correspond to a time instant at the end of the t-th watermark payload.

It is to be understood that multiple syntax elements may be combined to form the code. The code may then be mapped either by the AV presentation device 180 or using another server to different syntax element values. For example, the server information (e.g., location of the content and signaling server(s) and/or application layer protocol, etc.) and time code is combined into a single code. The single code is then mapped to a temporal location in the uncompressed audio-video stream, and location of the content and signaling server(s). In this manner, a single request may be made to the server for additional information.

A limited number of bits may be used for the time code, in such a manner to permits collisions in the time code. For example, using 20 bits for the timecode allows for at most 12 days of uniqueness at a granularity of 1 second. After 12 days the codespace corresponding to the timecode will be reused tending to result in collisions.

In one example the watermark payload may be encapsulated within a Standards Developing Organization (SDO) Private data command as SDO Payload using cmdID's. As an example the watermark payload of FIG. 5 or FIG. 6 maybe encapsulated as SDO payload. A cmdID value 0x05 may refer to a watermark based interactive services trigger (triggered declarative object (TDO) Model). A cmdID value 0x06 may refer to a watermark based interactive services trigger (direct execution model). This facilitates the re-use of existing segmentation and reassembly modules built for trigger transportation. The segmented command may be embedded in watermarks, if desired. The SDO Private data may be desired, such as illustrated in FIG. 13, where the packet is included as part of SDO_payload( ). In some examples the watermark payload received in this manner maybe passed to an entity and/or module in the receiver which handles these defined cmdID types. Then segmentation and reassembly functionality of that module could be reused if watermark payload packet needs to be split into multiple packets—depending upon the selected watermark scheme's capacity in terms of number of bits.

Parameter type T is a 2-bit field that indicates whether the instance of the SDOPrivatedata command is part of a segmented variable length command, as defined in Section 7.1.11.2 of CEA-708 (“CEA: “Digital Television (DTV) Closed Captioning, CEA-708-E, Consumer Electronics Association, June 2013”), and if so, whether the instance is the first, middle, or last segment. The Type field in the SDOPrivateData command is encoded as specified in Section 7.1.11.2 of CEA-708. pr is a flag that indicates, when set to ‘1’, that the content of the command is asserted to be Program Related. When the flag is set to ‘0’, the content of the command is not so asserted. Length (L) is an unsigned integer that indicates the number of bytes following the header, in the range 2 to 27, and is represented in the SDOPrivateData command as the set of bits L₄ through L₀ where L₄ is the most significant and L₀ is the least significant. cid (cmdID) is an 8-bit field that identifies the SDO that has defined the syntax and semantics of the SDO_payload( ) data structure to follow. The metadata may be encapsulated within SDO Private data as SDO Payload using cmdID's as shown in FIG. 14.

The payload defined in FIG. 5 and FIG. 6 may be encapsulated within a Standards Developing Organization (SDO) Private data (SDOPrivateData) command as SDO Payload using cmdID's. A cmdID value 0x05 and 0x06 may refer to encapsulation of payloads defined in FIG. 5 and FIG. 6 respectively. This facilitates the re-use of existing segmentation and reassembly modules built for trigger transportation. The segmented command may be embedded in watermarks, if desired. The SDO Private data may be desired, such as illustrated in FIG. 13, where the payload packet is included as part of SDO_payload( ).

The payload defined in FIG. 12 may be encapsulated within a Standards Developing Organization (SDO) Private data command as SDO Payload using cmdID's. A cmdID value 0x05 may refer to encapsulation of payload defined in FIG. 12. This facilitates the re-use of existing segmentation and reassembly modules built for trigger transportation. The segmented command may be embedded in watermarks, if desired. The SDO Private data may be desired, such as illustrated in FIG. 13, where the packet is included as part of SDO_payload( ).

Referring to FIG. 15, a transmitter of the system may receive one or more messages 530A, 530B, 530C that are to be embedded as a watermark into an essence (e.g., audio and/or video content). The one or more messages 530A, 530B, 530C may be packaged in the form of one or more fragments 520A, 520B, 520C. By way of example, each message may be packed in the form of a corresponding fragment. By way of example, each message may be packed in the form of one or more corresponding fragments. By way of example, a message may be partitioned each of which corresponds to a message fragment. In some cases, a message that exceeds the permitted length of a fragment may be spread into a plurality of corresponding fragments. In some cases, a long message may be spread over a plurality of corresponding fragments. In an example, each of the fragments is encoded to be transmitted only when there are no other fragments need to be transmitted. The transmitter may receive the message fragment(s) and create a series of one or more payloads 510 to be embedded within the essence. In some cases, the series may include embedding and/or sending the same message fragment(s) multiple times. In a typical example, one payload is embedded with one unit of the essence (e.g., one picture of the video and/or one segment of the audio). Each of the payloads 510 may include additional header and signaling information for the fragment(s). The essence, which may be for example a video picture and/or an audio segment, may be received by a watermark embedder 500 which embeds the payload 510 therein, to create a marked essence.

In an example system, it may be required that if a picture within a video segment carries a watermark then all the pictures within the video segment would carry a watermark. A receiver may then detect the loss of pictures by detecting that no watermark segment is being detected in the current video segment, whereas on an earlier occasion a picture within the video segment contained a watermark. A video segment would correspond to a group of consecutive pictures. Within a receiver a video segment may be identified by the watermark extractor by some external means.

Referring to FIG. 16, a decoder or receiver of the system may receive one or more marked essences, such as those provided by the transmitter of FIG. 15. A watermark payload extractor 600 extracts the payload(s) from the marked essence(s). One or more message fragments may be extracted 610 from the one or more payloads. The result of the extraction 610 is a series of one or more message fragments. Each of the one or more message fragments may be grouped appropriately (for e.g. using header information of the message fragment) and input to a message reassembly 620A, 620B, 620C. The result of the message reassembly 620A, 620B, 620C is a series of messages 630A, 630B, 630C. Each of the messages 630A, 630B, 630C may be the result of the reassembly of one or more fragments, which may be the result of one or more payloads, which may be the result of one or more marked essences. In an example the extracted and reassembled Message 1 (630A), . . . , Message (N−1) (630B), Message N (630C) in FIG. 16 will be respectively identical to the Message 1 (530A), . . . , Message (N−1) (530B), Message N (530C) in FIG. 15. By way of example, message reassembly may involve concatenating, in a particular order, the message data included in a group of message fragments.

In an example, a “1X” video watermark (emission format) delivers 30 bytes of payload data per video frame, while a “2X” video watermark (emission format) system delivers 60 bytes per frame. They are sometimes referred to as the 1X System and 2X System respectively.

The message fragment may include type information that indicates the particular type of information carried in the fragment. For example, the message type may indicate that the information includes a subset of a pre-defined set of syntax elements (e.g. content identifier, media time). In some cases, the values taken on by some syntax elements may be used to determine the exact subset of syntax elements included in the message fragment. For example, the message type may indicate that the information may include a channel identifier (ID). For example, the message type may indicate that the information may include a uniform resource identifier (URI), and a URI type. In another example, the message type may indicate that the information include a content identifier.

In an example, a message fragment may include a content identifier which may correspond to an Entertainment Identifier Registry (EIDR)

In an example, a message fragment may include a content identifier which may correspond to an Ad-ID used to track advertising assets.

In an example, the message fragment may include length information about variable length information included within it.

In an example, the watermark payload may include a message.

In an example, the message can be included within one message fragment.

In an example, a watermark payload may carry one or more message fragments.

In an example, a message fragment may include length information about the variable length information included within it, for e.g. URI, Ad-ID

In an example, the message fragment may include length information about a first variable length information included within the message fragment. The first variable length information may include a fixed length part and a second variable length information. The length of the second variable length information may be derived as the length of first variable length information minus the length of fixed length part. The length of the fixed length part may be derived in any suitable manner. For example, the fixed length part may be derived based upon the message type, the length of the first variable length information, the length of syntax elements belonging to a fixed length part included within the message fragment. In an example the length of part of the second variable length information included in a message fragment is derived as the length of the first variable length information minus the length of the fixed length part included in the message fragment. In an example the fixed length part included in a message fragment may not be included contiguously. In an example the fixed length part included in a message fragment may lie on either side of the second variable length information. In an example the fixed length part is only included partially within the message fragment. In an example the fixed length part may not be included within the message fragment.

In some audio-video environments it is desirable that the system has the capability to time-shift the audio-video content. Typically, this refers to recording the audio-visual content on a storage medium, such as a hard drive, and then watching the recorded show at a later time even if the recording is not yet complete. In some audio-video environments it is also desirable that the system is capable of trick mode functions, such as playback of previously recorded content, pause, pause-live, jump to next segment, jump to last segment, resume broadcast of live content, etc. In some audio-video environments it is desirable that the system has the capability to enable user preferences and interactive applications to be overridden as necessary in the event of an emergency alert (EA). Typically, emergency alerts are important messages that originate from the federal, state, or local governments that provide emergency information, such as earthquakes, floods, and other events that are national in nature and/or regional in nature. For such emergency alerts often provided with the audio visual content, it is desirable to be able to override the graphics being displayed on AV presentation device 180, such as video overlays or other graphical content, so that the emergency alert message is presented in a manner that is readily visible on the AV presentation device. For example, in the case that the viewer is watching video content on the AV presentation device such as a television together with another window open on the AV presentation device interacting with an interactive TV application, it is desirable to override both the video content and the interactive TV application so that the emergency alert message is readily visible on the AV presentation device. Merely displaying the emergency alert message in the video content may be insufficient in some situations where the video content is obscured by another application, such as the interactive TV application. In some audio-video environments to the extent that all of the emitted broadcast services are not available to viewers from a received broadcast television service from a MVPD, such as cable, satellite, or Internet Protocol Television (IPTV) operator, the system should be capable of enabling the receivers to retrieve the missing components of the services via alterative networks (e.g., broadband network connection). Often, this may include emergency alert messages and the contents thereof, which may not be made available to a AV presentation device 180 because a broadcast receiver device 160 (e.g., set top box) receiving the audio visual content is using a high definition multimedia interface (HDMI) to the AV presentation device that only provides uncompressed audio and video information to the AV presentation device while omitting other types of components that may otherwise have been desirable to provide to the AV presentation device. It is to be understood that the AV presentation device may be any device capable of rendering audio and/or visual content, and which may be networked together in a multi-screen interactive TV session.

While presenting broadcast audio-video content that is being contemporaneously provided by a broadcaster, any emergency alert messages that are included with the audio video content, such as being embedded within a watermark included within the audio and/or video content, the AV presentation device 180 with watermark capable receiver 310 and watermark client 320 will detect and respond to the emergency alert signal. However, in the case that the viewer has time-shifted the audio-video content, when the AV presentation device 180 receives the time-shifted audio-video content together with the watermark that includes the emergency alert signal, the AV presentation device 180 will likewise detect and respond to the emergency alert signal. While such delayed detection and response may be appropriate if the shift-shifting is of a minimal duration, this may result in a disruption to the viewer experience when the time-shifting is not of a minimal duration because often the emergency alert is no longer relevant. By way of example, when the time-shifting is not of a minimal duration the AV presentation device 180 with watermark capable receiver 310 and watermark client 320 will detect and respond to the emergency alert signal which may involve modifying the video content and may involve removing any other applications that are currently being presented on the AV presentation device 180, resulting in an unnecessary disruption in the viewing experience.

Referring to FIG. 17, it is desirable that an emergency alert watermark included within the audio and/or video content includes an expiry time value 700. The expiry time value 700 indicates a time value representative of the time extent of the corresponding emergency alert. For example, the time extent may be represented in terms of minutes in the case of audio and video watermarks, or in terms of seconds in the case of video watermarks. Preferably, the time extent is consistent with the textual content of the broadcasters' alert message. For example, a time extent until 5 PM would be appropriate for a broadcasters' alert message of “Flash Flood warning in effect till 5 pm.” It is also desirable that the emergency alert watermark included within the audio and/or video content includes an urgency flag 710. The urgency flag 710 signals to devices the extent to which immediate attention to the emergency alert is desirable. For example, if the urgency flag 710 is set then all on-screen display objects (e.g., an interactive TV application running on the AV presentation device 180, such as a television) may be cleared, even as the remainder of the emergency alert message is still being retrieved, so that the emergency alert message may be presented in a more urgent manner. For example, if the urgency flag 710 is not set, then the on-screen display objects are not necessarily cleared in such a timely manner, while the remainder of the emergency alert message is still being retrieved. In the case that the urgency flag 710 is not set, the emergency alert message may be further parsed and matched to further confirm its applicability to the current viewer. For example, the further processing may include geolocation processing to determine whether the message is applicable to the particular viewer.

It is also desirable that the emergency alert watermark included within the audio and/or video content includes a severity indicator 720. For example, the severity indicator 720 may include a range of values such as for example, extreme, severe, moderate, minor, and/or unknown. In this manner, the emergency alert signal may provide information relevant to the severity of the emergency event.

It is also desirable that the emergency alert watermark included within the audio and/or video content includes a certainty indicator 730. For example, the certainty indicator 730 may include a range of values such as for example, observed, likely, possible, unlikely, and/or unknown. In this manner, the emergency alert signal may provide information relevant to the certainty of the emergency event.

By providing the emergency alert watermark that includes the expiry time value 700, the urgency flag 710, the severity indicator 720, and/or the certainty indicator 730 enables broadcasters to flexibly signal to the receiver time-sensitive emergency alerts that are suitable for environments that include the redistribution via a MVPD broadcast receiving device 160 and/or time-shift use of audio-visual content. Preferably, the emergency alert signal that include the expiry time value 700, the urgency flag 710, the severity indicator 720, and/or the certainty indicator 730 are provided in the audio watermark and/or video watermark of the audio video content. Also, by providing the emergency alert signal that includes the expiry time value 700, the urgency flag 710, the severity indicator 720, and/or the certainty indicator 730 enables receivers to properly identify time sensitive alerts and provide a suitable response. Further, by providing the emergency alert signal that includes the expiry time value 700, the urgency flag 710, the severity indicator 720, and/or the certainty indicator 730 facilitates reducing unnecessary disruption to the viewer's experience, especially in the case of time-shifted audio video content. Moreover, by providing the emergency alert signal that includes the expiry time value 700, the urgency flag 710, the severity indicator 720, and/or the certainty indicator 730 provides information to the viewer so that the viewer may suitably respond to the emergency alert signal.

Referring to FIG. 18, the structure of the watermark message block 800 carried in the payload of watermark technology with moderate capacity such as video watermark may include a watermark message identification (wm_message_id) 802 which indicates the type of messages signaled by the watermark message block 800, such as an emergency alert signal and message. A watermark message block 800 may include a full wm_message( ) or a fragment of a wm_message( ). A table 805 may be used to select an appropriate set of watermark decoding and/or processing based upon the type of wm_message_id 802. In the case that the wm_message_id is 0x05 806 indicates that the watermark message block 800 includes an emergency alert signal and message (EA_message( )) 808. wm_message_bytes( ) includes a complete instance of the wm_message( ) identified by the value of wm_message_id when indicated (for e.g. via signaling) that no fragmentation is used, otherwise wm_message_bytes( ) includes a fragment of the wm_message( ). Other structures for the watermark message may likewise be used, as desired.

The structure of the EA_message( ) 808 may include one or more different data fields. The EA_message( ) 808 may include an EA_Expiry 852 that may be a 26-bit integer value that represents a Coordinated Universal Time (UTC) in minutes of granularity when the current emergency message ends. An EA_Expiry value of 0 indicates that the alert end time is unknown. In the receiving device, the UTC of the current time may be compared against the UTC of the EA_Expiry 852, which if the UTC of the current time is less than or equal to the UTC of the EA_Expiry 852 then the emergency alert event is still appropriate for being processed accordingly. In the case that the EA_Expiry 852 value is 0, indicating that the alert expiry time is unknown, then the AV presentation device 180 may automatically render the alert message. The EA_Expiry 852 corresponds to the expiry time value 700.

The EA_message( ) 808 may include an EA_Urgency 854 that may be a 1-bit value that represents the urgency of the emergency alert event. A value of 1 signals to the AV presentation device 180, such as a television, that immediate attention is preferred. A value of 0 signals to the AV presentation device 180, such as a television, that the alert is of normal urgency in nature. Such AV presentation device 180 may further propagate the signal to one or more companion devices that are currently in a networked multi-screen interactive TV session with the AV presentation device 180, such as a television. The EA_Urgency 854 corresponds to the urgency flag 710.

The EA_message( ) 808 may include an EA_message_body_present 856 that may be a 1 bit value that indicates the presence of additional data related to the EA_message 808.

The EA_message( ) 808 may include a reserve 4 bits 858 of padding for byte alignment.

The EA_message( ) 808 may include a conditional statement 860 signaling the additional data related to the EA_message 808.

The additional data may include an EA_message_ID 862 which may provides an ID for the emergency alert message.

The additional data may include an EA_message version 864 which may provide a version number for the emergency alert message.

The additional data may include an EA_message_text_length 866 which may be an 8-bit unsigned integer that gives the length of an EA_message_text 866.

The additional data may include the EA_message_text (8*N) 868 which may be a text string of the emergency alert text.

It is to be understood that the watermark message and/or any other fields therein may be structured in any suitable manner. It is to be understood that fewer and/or greater number of bits may be used for the signaling. It is to be understood that the data is preferably received in the audio and/or video watermarking, but may likewise be obtained in any other manner.

Referring to FIG. 19, another example for signaling a watermark message within video may include replacing the reserve 4 bits 858 with an EA_Certainty_severity_code 900 which indicates the certainty and/or the severity of the corresponding emergency message.

Referring to FIG. 20, a table represents the different combinations of the certainty and severity. The certainty 1000 may include a range of values such as for example, observed, likely, possible, unlikely, and/or unknown. To represent the 5 values by two bits, the unknown and unlikely may be combined. The severity 1010 may include a range of values such as for example, extreme, severe, moderate, minor, and/or unknown. To represent the 5 values by two bits, the unknown and minor may be combined.

Referring to FIG. 21, another example for signaling a watermark message within video may include replacing the reserve 4 bits 858 with reserve 6 bits 1102. In addition, signaling the watermark message within the video may include replacing the EA_Expiry 852 (26 bits) with EA_Expiry 1100 (32 bits). The 32 bits provides additional granularity to more appropriately signal the UTC time code using seconds granularity.

Referring to FIG. 22, another example for signaling a watermark message within video may include replacing the reserved 6 bits 1102 with reserve 2 bits 1104. In addition, signaling the watermark message within the video may include the EA_Certainty_severity_code 900.

Referring to FIG. 23, the structure of the watermark message block 800 included within the watermark suitable for audio content may include an emergency alert flag (EA_flag) 1200 having 1 bit which indicates the type of messages signaled by the watermark message, such as an emergency alert signal. When the EA_flag has a value of 0 then the watermark message is not of an emergency alert type. In this case, the watermark message preferably includes a server_code 1210 which may be a 22 bit code that is used to query an audio watermark server to obtain further information regarding the non-emergency alert message. The query may be of the form “http://{server_code}.vp1.tv/atsc30/interval_code, where the interval_code 1220 indicates a timeline location in the video content corresponding to the server_code 1210. A trigger 1230 may be provided to indicate that the previous one or more server_code and/or interval_code watermark data should be executed.

When the EA_flag 1200 has a value of 1 then the watermark message is of an emergency alert type. In this case, the watermark message preferably includes the server_code 1210 which may be a 22 bit code that is used to query the audio watermark server to obtain further information regarding the emergency alert message. The query may be of the form “http://{server_code}.vp1.tv/atsc30/AEA/?zip=zipcode, where the query includes the 5-digit postal ZIP code of the AV presentation device 180 with watermark capable receiver 310 and watermark client 320 to enable the server to provide the relevant emergency alert information to the such AV presentation device. The watermark message may also include EA_Expiry 1240 which may be a 22 bit code that is used to determine the expiration time. The watermark message may also include an EA_Urgency 1250 to indicate the urgency of the watermark message in a manner similar to that of EA_Urgency 854.

A system employing the audio visual watermarking may include a requirement that broadcasters who employ such watermark technology should ensure that whenever a broadcaster signals elsewhere in the emitted signal that an EA event is in effect, then the EA flag should be correspondingly set to 1 and that the wm_message_id be correspondingly set to 0x05.

A system employing the audio visual watermarking may include a requirement that broadcasters who employ such watermark technology should ensure that whenever a broadcaster signals elsewhere in the emitted signal that there is no EA event in effect, then the EA flag should be correspondingly set to 0 and that the wm_message_id be correspondingly not set to 0x05.

FIG. 24A represents an exemplary bitstream structure of the video watermark message block (wm_message_block( )) where:

wm_message_id is a value that uniquely identifies the syntax and semantics of the data bytes carried in the message block.

wm_message_version is a 4-bit value that may be incremented if and only if anything in the wm_message( ) changes, with wrap-around to 0 after the value reaches 15.

fragment_number is a 2-bit value that specifies the number of current message fragment minus 1.

last_fragment is a 2-bit value that specifies the fragment number of the last fragment used to deliver the complete wm_message( ). A value of ‘00’ in last_fragment indicates no fragmentation is used (the wm_message( ) contained within is complete). A value of ‘01’ in last_fragment indicates the wm_message( ) will be delivered in two parts, a value of ‘10’ indicates the wm_message( ) will be delivered in three parts, and a value of ‘11’ indicates it will be delivered in four parts. The pair of values fragment_number and last_fragment may be considered to signal “part M of N.”

wm_message_bytes( )—When the value of last_fragment is 0, wm_message_bytes( ) may be a complete instance of the watermark message identified by the value of wm_message_id. When the value of last_fragment is non-zero, wm_message_bytes( ) may be a fragment of watermark message wm_message( ). The concatenation of all instances of wm_message_bytes( ) with a given wm_message_id and wm_message_version number results in the complete wm_message( ) associated with that wm_message_id. The assembly of a wm_message( ) from one or more wm_message_block( ) instances may be as illustrated in FIG. 24C. wm_message_block(i) may indicate the i-th instance e.g. corresponding wm_message_block( ) instance with fragment_number value equal to i.

FIG. 24B is an exemplary mapping of wm_message_id to wm_message( ). It is used to determine the bytes included in wm_message_bytes( ).

In an example system, fragment_number is constrained to be less than or equal to last_fragment.

FIG. 24D, represent an exemplary URI Message used to deliver URIs of various types. The URI Message may be sent in fragments (e.g. the value of last_fragment in the message header may be non-zero). The value of field uri_type identifies the type of URI. The value of field uri_strlen signals the number of characters in the URI_string( ) field to follow. The field URI_string( ) is a URI consisting of characters whose values may be restricted to those allowed for Uniform Resource Identifiers (URIs) by Internet Engineering Task Force (IETF) Request for Comments (RFC) 3986 (https://www.ietf.org/rfc/rfc3986.txt, incorporated by reference herein in its entirety). The length of the URI string (URI_string( )) may be as given by the value of uri_strlen. The character string, after reassembly, if the URI is sent in fragments, is constrained to be a valid URI per RFC 3986.

In an example a pre-determined uri_type value may indicate that the URI message includes the URL for a Common Alerting Protocol (CAP) message. For example, according to the encoding given in FIG. 24E the value 0x04 for uri_type indicates that the URI message includes the URL for a CAP message. The value 0x04 is only an example. Other value may instead be used to indicate that the URI message includes the URL for a CAP message. For example a value of 0x09 or a value of 0xf0 may be used.

In an example, associated with some URI types (e.g. indicated by uri_type field) (or all URI types) an expiration field is signaled for e.g. in the URI Message. The expiration field may contain date and time information after which the URI is no longer valid. The expiration date and time information may be low order 32 bits from the 42-bit seconds field of precision time protocol (PTP) timestamp as defined in Institute of Electrical and Electronics Engineers (IEEE) 1588 (2008).

In an example, associated with some URI types (or all URI types) a valid_from field is signaled for e.g. in the URI Message. The valid_from field may contain date and time information before which the URI is not yet valid. The valid_from date and time information may be low order 32 bits from the 42-bit seconds field of PTP timestamp

FIG. 25A illustrates a flowchart of exemplary transmission of field based on a key field value. The value of a key field is transmitted in watermark 2500. The length of a field may be determined based on the transmitted value of the key field 2505. The value of the field may be transmitted using a number of bits corresponding to the determined length 2515. In an example the watermark is video watermark. In an example the key field is the watermark message id. In an example the fields whose length are determined are current fragment number and last fragment number. In an example the lengths of current fragment number and last fragment number are the same.

FIG. 25B illustrates a flowchart showing exemplary reception of a field based on a key field value. A key field is received in watermark 2550. The length of a field is determined based on the value of the key field 2555. The field is received from the watermark by parsing number of bits corresponding to the determined length 2565. In an example the watermark is video watermark. In an example the key field is the watermark message id. In an example the fields whose length are determined are current fragment number and last fragment number. In an example the lengths of current fragment number and last fragment number are the same.

In an example, a derived CAP message may be signaled in the video watermark (e.g. derived_emergency_alert_message( ) in FIG. 26B). A derived CAP message may include all or a subset of information from the original CAP message.

In an example, the original CAP message may be received from an external warning dissemination system.

In an example, the original CAP message may be formatted as specified in OASIS: “Common Alerting Protocol”. The current version of the OASIS: “Common Alerting Protocol” is 1.2 and is described at http://docs.oasis-open.org/emergency/cap/v1.2/CAP-v1.2-os.html.

In an example, a derived CAP message may include information in addition to the original CAP message. In an example, a derived CAP message may also exclude certain information from the original CAP message.

In an example, a derived CAP message may use the formatting as specified in OASIS: “Common Alerting Protocol” described above.

In an example, a derived CAP message may be signaled in the video watermark even when there exists no original CAP message, for e.g. a station is aware of a local emergency before the national warning system.

In an example, a derived CAP message may not be signaled in the video watermark even when there exists an original CAP message.

In an example, the derived CAP message may be signaled over-the-air.

In an example, a derived CAP message may correspond to a warning/alert message.

In an example system, the length of certain fields in the video watermark message block may be derived based on the value of some other fields in the video watermark message.

In an example system, the maximum value of certain fields in the video watermark message block may be derived based on the value of some other fields in the video watermark message block.

In an example the derived CAP message may be a emergency alert message not formatted as a CAP message.

FIG. 26A represents an exemplary bitstream structure of the video watermark message block (wm_message_block( )) where the length and maximum value of fields fragment_number and last_fragment depend on value of wm_message_id field. This allows fragmenting of a message into more than a particular single fixed number of fragments. For example when using the bitstream structure shown in FIG. 24A, a message can be fragmented into at most four fragments. Each fragment may have limited data capacity. Thus overall data capacity when using structure shown in FIG. 24A is limited. In comparison allowing using more number of bits for fragment_number and last_fragment fields allows using more number of fragments for the message. Thus larger messages could be sent. At the same time for sending smaller messages the overhead of sending higher number of bits for fragment_number and last_fragment field is avoided. Thus the message dependent fragment field signaling provides a good trade-off between flexibility and bit-savings.

Listed below is an exemplary semantic for various fields in FIG. 26A:

wm_message_id is a value that uniquely identifies the syntax and semantics of the data bytes carried in the message block.

wm_message_version is a 4-bit value which may be incremented if and only if anything in the wm_message( ) changes, with wrap-around to 0 after the value reaches 15.

fragment_number is a value that specifies the number of current message fragment minus 1. fragment number field has length equal to num_fragment_bits bits as specified in table A below.

last_fragment is a value that specifies the fragment number of the last fragment used to deliver the complete wm_message( ). last_fragment field has length equal to num_fragment_bits bits as specified in table A below. The range of allowed unsigned integer values for last_fragment field is 0 to (2^(num_fragment_bits)−1). A string of ‘0’ values of length num_fragment_bits in last_fragment indicates no fragmentation is used (the wm_message( ) contained within is complete).

wm_message_bytes( )—When the value of last_fragment is 0, wm_message_bytes( ) may be a complete instance of the watermark message identified by the value of wm_message_id. When the value of last_fragment is non-zero, wm_message_bytes( ) may be a fragment of that watermark message wm_message( ). The concatenation of all instances of wm_message_bytes( ) with a given wm_message_id and wm_message_version number results in the complete wm_message( ) associated with that wm_message_id. The assembly of a wm_message( ) from one or more wm_message_block( ) instances may be as illustrated in FIG. 26C. wm_message_block(i) may indicate the i-th instance e.g. corresponding wm_message_block( ) instance with fragment_number value equal to i.

TABLE A num_fragment_bits (in wm_message_id bits) 0x01 2 0x02 2 0x03 2 0x04 2 0x05 2 0x06 10 0x07 to 0xFF 2

In an example wm_message_id would define not only num_fragment_bits (in bits) of some fields but would also define the length of a reserved field that makes the size of the watermark message block (wm_message_block( )) a multiple of 8-bits.

In an example, a decimal value of 0 for last_fragment field indicates no fragmentation is used (the message contained within is complete). A decimal value of ‘xyz’ in last_fragment indicates the message will be delivered in xyz parts.

In an example a range of wm_message_id values would correspond to a maximum number of message fragments allowed.

In an example a range of wm_message_id values would correspond to a value for num-fragment_bits (in bits). In an example a range of wm_message_id values would define the length of a reserved field that makes the size of the watermark message block (wm_message_block( )) a multiple of 8-bits.

A system employing the audio visual watermarking may at the discretion of the broadcasters include setting the expiration times to 0 to alleviate the need to determine suitable time duration and/or ending time.

A system employing the audio visual watermarking may determine the expiration times based upon other elements included within the audio visual content or otherwise available to the display device.

Moreover, each functional block or various features of the base station device and the terminal device (the video decoder and the video encoder) used in each of the aforementioned examples may be implemented or executed by a circuitry, which is typically an integrated circuit or a plurality of integrated circuits. The circuitry designed to execute the functions described in the present specification may comprise a general-purpose processor, a digital signal processor (DSP), an application specific or general application integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, discrete gates or transistor logic, or a discrete hardware component, or a combination thereof. The general-purpose processor may be a microprocessor, or alternatively, the processor may be a conventional processor, a controller, a microcontroller or a state machine. The general-purpose processor or each circuit described above may be configured by a digital circuit or may be configured by an analogue circuit. Further, when a technology of making into an integrated circuit superseding integrated circuits at the present time appears due to advancement of a semiconductor technology, the integrated circuit by this technology is also able to be used.

The programs which run on the apparatuses according to the present invention may be programs which cause a computer to function by controlling a central processing unit (CPU) to implement embodiments of the present invention. The programs or information handled by such programs may be temporarily stored in a volatile memory such as a random access memory (RAM) or a hard disk drive (HDD) or a non-volatile memory such as a flash memory, or other memory storage system.

Programs for implementing the functions of the invention may be recorded on a computer-readable recording medium. The functions may be implemented by causing a computer system to read the programs recorded on the recording medium and execute the programs. The “computer system” may be a computer system embedded in the apparatus, and may include an operating system or hardware such as peripheral devices. The “computer-readable recording medium” may be a semiconductor recording medium, an optical recording medium, a magnetic recording medium, a recording medium that dynamically stores the program for a short period of time, and any other recording medium which is computer-readable.

The features or functional blocks of the apparatuses used in the aforementioned embodiments may be implemented or executed in circuitry, for example, an integrated circuit or a plurality of integrated circuits. The circuitry designed to perform the functions stated in the present specification may include a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof. The general-purpose processor may be a microprocessor, or may be any conventional processor, controller, microcontroller, or state machine. The above-described circuitry may be a digital circuit, or may be an analog circuit. In a case where an advanced semiconductor technology introduces a new integrated circuit technology for replacing the current integrated circuit, the invention may be implemented using such new integrated circuit technology.

It is to be understood that the claims are not limited to the precise configuration and components illustrated above. Various modifications, changes and variations may be made in the arrangement, operation and details of the systems, methods, and apparatus described herein without departing from the scope of the claims. 

The invention claimed is:
 1. A method for receiving a watermark message, said watermark message containing at least one watermark message block, comprising the steps of: (a) receiving said at least one watermark message block; (b) determining a watermark message id from at least one of said at least one watermark message block; (c) determining a fragment characteristic information for each of said at least one watermark message block, wherein a length of said fragment characteristic information is based upon on a value of said watermark message id; (d) recovering said watermark message from said at least one watermark message block based upon said fragment characteristic information.
 2. The method of claim 1 where said fragment characteristic information contains a fragment number that specifies an ordering of said at least one watermark message block.
 3. The method of claim 1 where said fragment characteristic information contains a last fragment field that specifies a number of said at least one watermark message block in said watermark message.
 4. The method of claim 1 where said length of said fragment characteristic information is 4 bits for a first watermark message id and a length of the fragment characteristic information is 20 bits for a second watermark message id.
 5. A method for receiving a watermark message, said watermark message containing at least one watermark message block, comprising the steps of: (a) receiving said at least one watermark message block; (b) determining a watermark message id from at least one of said watermark message block; (c) determining if a fragment characteristic information is present for each of said at least one of said watermark message block, wherein said determining if a fragment characteristic information is present depends on a value of said watermark message id; (d) recovering said watermark message from said at least one watermark message block based upon said fragment characteristic information.
 6. The method of claim 5 where said fragment characteristic information is a reserved field value.
 7. A device that includes a processor configured to receive a watermark message, said watermark message containing at least one watermark message block, comprising: (a) said device receiving said at least one watermark message block; (b) said device determining a watermark message id from at least one of said at least one watermark message block; (c) said device determining a fragment characteristic information for each of said at least one watermark message block, wherein a length of said fragment characteristic information is based upon on a value of said watermark message id; (d) said device recovering said watermark message from said at least one watermark message block based upon said fragment characteristic information.
 8. The device of claim 7 where said fragment characteristic information contains a fragment number that specifies an ordering of said at least one watermark message block.
 9. The device of claim 7 where said fragment characteristic information contains a last fragment field that specifies a number of said at least one watermark message block in said watermark message.
 10. The device of claim 7 where said length of said fragment characteristic information is 4 bits for a first watermark message id and a length of the fragment characteristic information is 20 bits for a second watermark message id.
 11. A device that includes a processor configured to receive a watermark message, said watermark message containing at least one watermark message block, comprising: (a) said device receiving said at least one watermark message block; (b) said device determining a watermark message id from at least one of said watermark message block; (c) said device determining if a fragment characteristic information is present for each of said at least one of said watermark message block, wherein said determining if a fragment characteristic information is present depends on a value of said watermark message id; (d) said device recovering said watermark message from said at least one watermark message block based upon said fragment characteristic information.
 12. The device of claim 11 where said fragment characteristic information is a reserved field value. 